The purposes of the proposed work are: (1) To continue to study two human skin cell culture systems which thus far have shown interesting changes suggestive of transformation after inoculation with purified human wart virus. These studies would include characterization and identification of the non-virion cellular antigens already detected in these cultures by immunofluorescence and complement-fixation, search for evidence of the viral genome in these cells using biochemical techniques, and further trials of their tumorigenic capacity in an intact host. (2) To continue to investigate the non-virion new cellular antigens (neoantigens) which appear to be viral-induced and which also have been detected by immunofluorescence in sections of human warts and condylomata acuminata employing sera from certain types of wart patients and experimental guinea pig sera. (3) To apply these sera in search of similar wart virus-induced antigens in a variety of human epidermal tumors. (4) To attempt to reproduce the experiments of Eisinger et al. who reported the in vitro production of a cytolytic infection with wart virus. In these experiments the appearance of mature virions as well as of non-virion new antigens will be followed. (5) To study the role of cell-mediated immunity in human wart virus infections, especially the reactions of T and B lymphocytes and macrophages in patients with limited as opposed to widespread evidence of disease and in those undergoing spontaneous regression.